Gripper looms



W. SCHEFFEL Aug. 1 5, 1967" GRIPPER LOOM3 2 Sheets-Shem L Filed June 25, 1965 Fig.1

In vent or:

W. SCHEFFEL 'GRIPPER LOOMS 2 Sheets-Sheet Z-z Filed June 25, 1965 Inventor:

United States Patent GRIPPER LOOMS Walter Scheffel, 53 Industriestrasse, Weissenhurg, Bavaria, Germany Filed June 23, 1965, Ser. No. 466,394 Claims priority, application Germany, June 26, 1964, Sch 35,388 3 Claims. (Cl. 139-122) This invention relates to a shuttleless loom of the type sometimes known as a gripper loom. In looms of this kind, the weft yarns are picked into the warp by means of two inserters or grippers. To this end, one inserter or gripper moves from one side of the loom into the shed just after the latter has opened and carries the weft yarn substantially to the center of the shed where it transfers the Weft yarn to the other inserter or gripper which has moved simultaneously into the shed from the other side. Immediately after the weft yarn has been transferred from one gripper to the other in the center of the shed, the two grippers withdraw from the shed, the gripper to which the weft yarn has been transferred drawing the weft through to the edge of the cloth. The inserted weft yarn is then beaten up by a slay, whereafter a new shed is formed and picking is repeated.

The grippers are each mounted, for instance, on a rigid rod adapted to reciprocate them. Since the driving power for the grippers is, as a rule, available in the form of a rotating force, the rotation thereof must be conlverted into a reciprocating movement. In the known gripper-driving mechanism, this means that fairly large inertia forces must be dealt with at each reversal of the direction of movement of the grippers. To ensure that these inertia forces do not cause overstressing, the grippers must reciprocate at a fairly low speed, with theresult that looms of this kind operate fairly slowly.

It is a principal object of this invention to considerably increase the working speed of the gripper looms, this being achieved by the masses which must be reversed at each gripper end position.

According to a main feature of the invention, the driving mechanism adapted to reciprocate each gripper rod and associated gripper consists exclusively of elements all rotating in the same direction, the elements comprising: a. rotating member driven continuously in one direction; a main crank connected to a shaft associated with the rotating member; and an auxiliary crank whose shaft is rotatably mounted in the main crank at an eccentric position thereof, the last-mentioned shaft having rigidly connected to it, at the end remote from its crank web, a rotating member; and a stationary circular element of twice the diameter of the last-mentioned rotating member disposed concentrically of the shaft of the main crank, the rotating member and the circular element being positively connected to one another, the gripper rod being articulated to the crank pin of the auxiliary crank.

In such a drive for each gripper, the only elements present, apart from the gripper and the gripper rod, are elements which rotate continuously to the same handi.e. whose direction of rotation does not have to be reversed. All that requires reversal at the end positions is the direction of movement of the gripper and of the rod connected thereto. The weight of the gripper and of the gripper rod can be fairly low so that the gripper speed can be much higher than previously without excessive inertia occurring. Consequently, the speed of the loom can be increased considerably, yet it runs fairly quietly.

Advantageously, the rotating member and the circular element are interconnected by an endless toothed belt. conveniently, the rotating member is a toothed wheel adapted for use with a toothed belt and is connected via 3,335,760 Patented Aug. 15, 1967 a toothed belt to another similar toothed wheel driven directly by the loom main shaft.

The invention will be described further, by way of example, with reference to the accompanying drawings wherein:

FIG. 1 is a diagrammatic front elevation of a gripper loom according to the invention;

FIG. 2 is a diagrammatic side elevation of the loom shown in FIG. 1;

FIG. 3 an enlarged detail of the right-hand part of the loom shown in FIG. 1 with particular emphasis on the mechanism for driving the gripper disposed on the righthand side of the loom;

FIG. 4 is a part-sectional side elevation of part of the gripper-driving mechanism; and

FIG. 5 is a diagram showing how the gripper-driving mechanism operates.

The loom shown is generally of conventional construction save for the mechanism for driving the grippers. A slay 2 is mounted, by way of a shaft 3, on loom frame 1 for pivoting movement. A main drive shaft 4 of the loom is rotatably mounted in the loom frame 1 and is rotated by a spur gear wheel 5 engaging with a pinion 6 driven by an electric motor 7 secured to base 8 of loom frame 1. Eccentrics 9 are secured to main drive shaft 4 and rings 10, 11 are mounted on eccentrics 9. These rings are rigidly connected to arms 12, 13 which are pivotally connected to the slay 2 and which, as the main drive shaft 4 rotates, pivot the slay 2 backwards and forwards as indicated by arrow A in FIG. 2. Weft yarns are supplied by bobbins 14, 15 mounted on inclined arms 16, 17. Picking is performed by inserters or grippers 18, 19 secured each to a respective gripper rod 20, 21. The gipper rods 20, 21 can be, for instance, of tubular form. The rods 20, 21 are connected, at their ends remote from the respective grippers, to driving mechanisms 22, 23 which form the subject matter of the present invention.

The loom also comprises harness shafts or harness frame 24, 25, 26 and 27 connected in usual manner to a harness shaft or top roller 28. Also provided are a warp beam 29 and a backrest 30. Cloth woven on the loom passes over an emery beam 31 to a cloth beam 32. The harness shafts or harness frame 24 to 27 are operated conventionally, for instance, by eccentrics.

To explain the construction and operation of the gripper-driving mechanisms, consideration will be given to the mechanism 23. As can be seen from FIGS. 3 and 4, the loom frame 1 has mounted on it a cantilever arm 33, and a shaft 34 is so mounted at the free end of the arm 33 as to be rotatable. The shaft 34 has a toothed drive pulley 35 at one end, the toothed drive pulley 35 having a toothed belt 45 extending therearound; at its other end, the shaft 34 is so connected to a main crank 36 as to rotate therewith. At the eccentric location where there would normally be a crank pin, the main crank 36 has a socket receiving a spindle shaft 37 of an auxiliary crank 38 having a crank pin 39 to which the gripper rod 21 is pivotally connected. Secured to the shaft 37, on the side remote from the web of the auxiliary crank 38, is a toothed wheel 40 around which extends a toothed belt 42 which also extends around another and similar toothed wheel 41. Cantilever arm 33 is unitary with and in coaxial alignment with the wheel 41. The wheel 41 is twice the diameter of the wheel 40 and is concentric with the shaft 34. The endless toothed belt 42 couples together the wheels 40, 41. Distance B from the center of the crank pin 39 to the center of the shaft 37 is identical to distance C from the center of the shaft 37 to the center of the shaft 34.

When the shaft 34 performs one single revolution, the main crank 36 performs one complete revolution, the wheel 40 rotating because it rolls on the belt 42. Since the wheel 40 is half the size of the wheel 41, the wheel 40 performs two complete revolutions for every single revolution of the shaft 34. Since the distance B equals the distance C, during one complete revolution of the shaft 34 the crank pin 39 moves along a line D, which extends through the center of the shaft 34, from one end position E to its other end position F, then back to the position E. Consequently, as the rotating member 35 rotates continuously in one direction, the crank pin 39 moves along the line D, such line passing through the axis of the toothed wheel 35. The throw H of the crank pin 39 and therefore of the gripper 19 equals 4 B. The horizontal extension of the line D coincides with the vertical center of each new shed 43 (FIG. 2) which is formed. Members 44 for guiding the gripper rod 21 are provided on the cantilever arm 33, and as the shaft 34 rotates the gripper rod 21 is reciprocated along a line passing through the center of the shaft 34 and extending symmetrically between the members 44.

The drive pulley 35 is driven by way of the belt 45 from a drive wheel 46 on a shaft 47. Rigidly connected to the latter is a bevel gear 48 which meshes with a bevel gear 49 on the main drive shaft 4.

I claim:

1. A shuttleless loom comprising means for forming a warp shed, a pair of weft inserters disposed one at each side of said shed, and, for each of said inserters, an inserter driving mechanism for reciprocating the respective inserter into and out of said shed for alternate (a) insertion of a weft yarn half way across said shed for subsequent withdrawal by the other of said inserters and (b) taking up of and withdrawal of a weft yarn inserted into said shed by the said other of said inserters, each said inserter driving mechanism comprising a first rotating member adapted to be rotated continuously in one direction, a first shaft driven by said first rotating member, a main crank mounted on said first shaft, a second shaft journalled eccentrically in said main crank, an auxiliary crank mounted on said second shaft, a crank pin on said auxiliary crank and connected to the respective one of said inserters, a second rotating member mounted on said second shaft, a stationary circular element of diameter equal to twice the diameter of said second rotating member, disposed concentrically of said first shaft, coupling means between said second rotating member and said stationary circular element constraining said second rotating member to rotate said sec-ond shaft as said first shaft is rotated whereby said inserter performs a reciprocating movement along a linear path extending through the axis of said first shaft.

2. A shuttleless loom comprising means for forming a warp shed, a pair of weft inserters disposed one at each side of said shed, and, for each of said inserters, an inserter driving mechanism for reciprocating the respective inserter into and out of said shed for alternate (a) insertion of a weft yarn half way across said shed for subsequent withdrawal by the other of said inserters and (b) taking up of and withdrawal of a weft yarn inserted into said shed by the said other of said inserters, each said inserter driving mechanism comprising a first rotating member adapted to be rotated continuously in one direction, a first shaft driven by said first rotating member, a main crank mounted on said first shaft, a second shaft journalled eccentrically in said main crank, an auxiliary crank mounted on said second shaft, a crank pin on said auxiliary crank and connected to the respective one of said inserters, a first toothed wheel mounted on said second shaft, a stationary second toothed wheel of diameter equal to twice the diameter of said first toothed wheel, disposed concentrically of said first shaft, a toothed belt extending around said first toothed wheel and said second stationary toothed wheel and constraining said first toothed wheel to rotate said second shaft as said first shaft is rotated whereby said inserter performs a reciprocating movement along a linear path extending through the axis of said first shaft.

3. A shuttleless loom comprising a main drive shaft, means for forming a warp shed, a pair of weft inserters disposed one at each side of said shed, and, for each of said inserters, an inserter driving mechanism for reciprocating the respective inserter into and out of said shed for alternate (a) insertion of a weft yarn half way across said shed for subsequent withdrawal by the other of said inserters and (b) taking up of and withdrawal of a weft yarn inserted into said shed by the said other of said inserters, each said inserter driving mechanism comprising a first toothed drive pulley driven from said main drive shaft, a second toothed drive pulley, a first toothed drive belt extending around said first and second toothed drive pulleys, a first shaft driven by said second toothed drive pulley, a main crank mounted on said first shaft, 21 second shaft journalled eccentrically in said main crank, an auxiliary crank mounted on said second shaft, a crank pin on said auxiliary crank and connected to the respective one of said inserters, a first toothed wheel mounted on said second shaft, a stationary second toothed wheel, of diameter equal to twice the diameter of said first toothed wheel, disposed concentrically of said first shaft, a second toothed belt extending around said first toothed wheel and said stationary second toothed wheel and constraining said first toothed wheel to rotate said second shaft as said first shaft is rotated whereby said inserter performs a reciprocating movement along a linear path extending through the axis of said first shaft.

References Cited UNITED STATES PATENTS 1,794,943 3/1931 Butterworth u 139123 X 1,873,038 8/1932 Robertson 139 -123 2,816,576 12/1957 Shimwell 139-123 2,837,124 6/1958 Ancet al. 139-123 FOREIGN PATENTS 504,677 8/ 1951 Belgium. 378,197 7/ 1923 Germany.

21,839 of 1910 Great Britain. 966,710 8/ 1964 Great Britain.

MERVIN STEIN, Primary Examiner.

J. KEE CHI, Examiner. 

1. A SHUTTLELESS LOOM COMPRISING MEANS FOR FORMING A WARP SHED, A PAIR OF WEFT INSERTERS DISPOSED ONE AT EACH SIDE OF SAID SHED, AND, FOR EACH OF SAID INSERTERS, AN INSERTER DRIVING MECHANISM FOR RECIPROCATING THE RESPECTIVE INSERTER INTO AND OUT OF SAID SHED FOR ALTERNATE (A) INSERTION OF A WEFT YARN HALF WAY ACROSS SAID SHED FOR SUBSEQUENT WITHDRAWAL BY THE OTHER OF SAID INSERTERS AND (B) TAKING UP OF AND WITHDRAWAL OF A WEFT YARN INSERTED INTO SAID SHED BY THE SAID OTHER OF SAID INSERTERS, EACH SAID INSERTER DRIVING MECHANISM COMPRISING A FIRST ROTATING MEMBER ADAPTED TO BE ROTATED CONTINUOUSLY IN ONE DIRECTION, A FIRST SHAFT DRIVEN BY SAID FIRST ROTATING MEMBER, A MAIN CRANK MOUNTED ON SAID FIRST SHAFT, A SECOND SHAFT JOURNALLED ECCENTRICALLY IN SAID MAIN CRANK, AN AUXILIARY CRANK MOUNTED ON SAID SECOND SHAFT, A CRANK PIN ON SAID AUXILIARY CRANK AND CONNECTED TO THE RESPECTIVE ONE OF SAID INSERTERS, A SECOND ROTATING MEMBER MOUNTED ON SAID SECOND SHAFT, A STATIONARY CIRCULAR ELEMENT OF DIAMETER EQUAL TO TWICE THE DIAMETER OF SAID SECOND ROTATION MEMBER, DISPOSED CONCENTRICALLY OF SAID FIRST SHAFT, COUPLING MEANS BETWEEN SAID SECOND ROTATING MEMBER AND SAID STATIONARY CIRCULAR ELEMENT CONSTRAINING SAID SECOND ROTATING MEMBER TO ROTATE SAID SECOND SHAFT AS SAID FIRST SHAFT IS ROTATED WHEREBY SAID INSERTER PERFORMS A RECIPROCATING MOVEMENT ALONG A LINEAR PATH EXTENDING THROUGH THE AXIS OF SAID FIRST SHAFT. 